(F) Immunofluorescence with anti-Ki67 (green) identifies the proliferating cells of the skin, restricted to the basal layer of the epidermis and developing hair follicles. Anti-β4 int labeling reveals the presence of the hemidesmosomal integrin β4, restricted to the base of cells adhering to the underlying basement membrane. The white dotted line marks the outermost surface of the skin.